This invention relates generally to a system and method of updating a computer system""s BIOS (basic input/output system), and relates more particularly to a system and method of updating a video BIOS independently from the system BIOS.
In currently-known computer systems which incorporate a graphics chip on the motherboard, the video BIOS is formed as part of the overall computer system""s BIOS. For this reason, it is currently not possible to update the video BIOS independently from the system BIOS in the existing BIOS architectures. In the existing BIOS architectures, entirely new system BIOS must be loaded into the computer system in order to update the video BIOS.
The typical sequence of operation utilized to update the existing system BIOS involves the use of a xe2x80x9chot key sequencexe2x80x9d and a floppy disk. In this typical sequence, the computer is initially turned off, and the floppy disk containing the new system BIOS is loaded into the floppy-disk drive. Next, the xe2x80x9chot key sequencexe2x80x9d is pressed and held while the computer is turned on, which actuates the update of the existing system BIOS with the new system BIOS.
In accordance with the present invention, a computer system""s existing video BIOS is updated independently without the need for updating the computer system""s entire system BIOS, by transferring a new video BIOS contained on a floppy disk into a flash memory block dedicated for video-BIOS storage. The present invention incorporates a security measure to ensure that only new video BIOSs known to the system BIOS are used to update the existing video BIOS.
The video-BIOS update mode is entered through pressing and holding a xe2x80x9chot key sequencexe2x80x9d and turning on the computer. Once the hot key sequence has been detected, the system BIOS reads the new video BIOS from the floppy disk and performs a security check to ensure that the new video BIOS contained on the floppy disk is known to the system BIOS. The security check involves decoding the digital signature of the new video BIOS with a corresponding public key stored with the system BIOS. Once the security check has been completed, the system BIOS writes the new video BIOS into memory, e.g., a dedicated 64K flash-memory block.
In addition to facilitating updates of the video BIOS independent of the system BIOS, xe2x80x9cchipset patchesxe2x80x9d may be loaded onto a chipset along with the new video BIOS. A xe2x80x9cchipset patchxe2x80x9d is a code segment that may be run to fix problems on the chipset. The chipset patches are utilized to fix detected problems on the chipset by means of setting register bits within the chipset to proper values.